ABYC A-01: Marine Liquified Petroleum Gas Systems

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By Authority Of

THE UNITED STATES OF AMERICA

Legally Binding Document

By the Authority Vested By Part 5 of the United States Code § 552(a) and
Part 1 of the Code of Regulations § 51 the attached document has been duly
INCORPORATED BY REFERENCE and shall be considered legally
binding upon all citizens and residents of the United States of America.
HEED THIS NOTICE : Criminal penalties may apply for noncompliance.

Document Name: ABYC A-01 : Marine Liquified Petroleum Gas Systems

CFR Section(s) : 46 CFR 1 84.240(a)

Standards Body: American Boat and Yacht Council

A-l(9)
8/19/93

A-l MARINE LIQUEFIED PETROLEUM GAS (LPG) SYSTEMS

Based on ABYC's assessment of the state of existing
technology and the problems associated with achieving
the requirements of the standard, /1BYC recommends
compliance with this standard by August I, 1994,

1.1

PURPOSE

These voluntary technical practices and engineering
standards are guides for the design, construction and
installation of Liquefied Petroleum Gas (LPG) systems on
boats.

1.2

SCOPE

These voluntary teclmical practices and engineering
standards apply to all Liquefied Petroleum Gas (LPG)
Systems used for cooking, heating and refrigeration on all
boats up to the point of interlace with the appliance.
These recommended practices and engineering standards
do not apply to Liquefied Petroleum Gas (LPG) systems
used for internal combustion engines.

NOTES: I Attention is directed to the U.S. Coast

Guard Regulations which prohibit the use of Liquefied
Petroleum Gas (L PG) on certain vessels an d sets
different standards for Small Passenger Vessels
(reference 46 CFR Part 184 J).

2. Requirements for Compressed
Natural Gas t (CNG) are covered by ABYC A-22 }
"Marine - Compressed Natural Gas (CNG) Systems".

3. Requirements for LPG galley stoves
are covered by ABYCA-3, "Gallery Stoves ".

4. Requirements for LPG heating are
covered by ABYC A-7.

5. Requirements for appliances with
integral LPG cylinders are covered by ABYC A-30.

6. Requirements for other LPG fueled
appliances are covered by ABYC A-26, (Draft in
committee).

1,3

DEFINITIONS

Accessible - Capable of being reached for inspection,
removal or maintenance without removal of permanent
boat structure.

Cylinder - Any vessel or container used to transport or
store LPG.

Liquefied Petroleum Gas (LPG) - Includes any products
predominately composed of any of the following
hydrocarbons: propane, propylene, butanes (normal
butane or isobutane), butylenes, or a mixture thereof (with
physical properties as listed in the Appendix).

Locker - An enclosure intended for storage of one or more

cylinders.

Readily Accessible - Capable of being reached quickly and
safely for effective use under emergency conditions
without the use of tools.

System - The arrangement of cylinders, safety devices,
regulators, connections, valves, piping, tubing, hose,
fittings and devices intended to store, supply, monitor or
control the flow of fuel gas up to but not including the
appliance.

1.4

REFERENCED ORGANIZATIONS

ABYC - American Boat & Yacht Council, 3069 Solomon's
Island Road, Edgewater, MD 21037-1416. (410)956-
1050.

ASME - American Society of Mechanical Engineers, 345
E. 47th Street, New York, NY 10017,, (212)705-7722.

ASTM - American Society for Testing and Materials,
1916 Race Street, Philadelphia, PA 19103. (215)299-
5400.

DOT - Department of Transportation, 400 Seventh Street,
S,W., Washington, DC. 20590. (202)366-4000.

SAE - Society of Automotive Engineers, 400
Commonwealth Drive, Warrendale, PA 15096. (412)776-
4841.

IJL - Underwriters Laboratories, Inc., 12 Laboratory Drive,
P.O. Box 13995, Research Triangle Park, NC 27709.
(919)549-1565.

1.5

REQUIREMENTS - IN GENERAL

1 .5.1 Comprehensive printed instructions and a
labeled diagram(s) covering details of proper installation,
maintenance and operation shall be provided with each
LPG system installed on a boat. These instructions shall
include that a test be made every time the cylinder supply
valve is opened for use and after any events which may
have affected the system such as grounding, fire, or
collision.

1.5.2 Each system shall be fitted with a pressure
gauge. The gauge shall read the cylinder pressure side of
the pressure regulator.

€> 1993 American Boat and Yacht Council, Inc.

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NOTE: The purpose of the gauge is to provide a quick
and easy way to test the system for leakage.

L5.3 All components of LPG systems subject to
cylinder pressures shall have a rated pressure of at least
1,725 KPA above ambient (250 pounds per square inch
gauge).

1.5.4 With each LPG system installed on a boat a sign
shall be provided. It shall be located in the immediate
vicinity of the cylinder enclosure and shall be plainly
visible.

The sign shall withstand the effects of exposure to water,
oil, salt spray, direct sunlight, heat, cold and wear
expected in normal operation of a boat without loss of
legibility, and shall include the following informational
elements:

(1)

CAUTION

THIS SYSTEM IS DESIGNED FOR USE WITH
LIQUEFIED PETROLEUM GAS (LPG) ONLY. DO
NOT CONNECT COMPRESSED NATURAL GAS
(CNG)TOTHIS SYSTEM.

(2) Keep cylinder valve(s) and solenoid valve(s)

closed when boat is unattended. Close them immediately
in any emergency. When on board, cylinder valve(s) or
solenoid valve(s) shall be closed when appliances are not
in use. Keep empty cylinder valvc(s) tightly closed.

(3)
valve.

Close appliance valves before opening cylinder

(4) Test for system leakage each time the cylinder
supply valve is opened for appliance use. Close all
appliance valves. Open solenoid valve if installed. Open,
then close cylinder supply valve. Observe pressure gauge
at the regulating device and see that it remains constant
for not less than three minutes before any appliance is
used. If any leakage is evidenced by a pressure drop,
check system with a leak detection fluid or detergent
solution which does not contain ammonia and repair-
before operating system.

(5) NEVER USE FLAME TO CHECK FOR
LEAKS

This sign shall be installed in the vicinity of the cylinder
and shall be plainly visible.

1.5,5 On boats which have a gasoline engine, the sign
shall also contain at least the following:

A

WARNING

GASOLINE VAPORS ARE EXPLOSIVE.

OPEN FLAME APPLIANCES CAN IGNITE

GASOLINE VAPOR CAUSING FIRE OR

EXPLOSION.

TURN OFF ALL OPEN FLAME
APPLIANCES WHEN FUELING!

1.5.6 The system and all its components shall be
capable of operation within an ambient temperature range
of from -18°C (0°F) to +60° (140°F).

1.5.7 Only systems using LPG cylinders of the vapor
withdrawal type are permitted. Cylinders designed or
installed so as to admit liquefied gas into any other part of
the system are prohibited.

1.5.8 All devices and appliances using LPG shall be
secured so as to prevent upset or displacement that will
place strain upon fuel distribution system or appliance
connections.

1.6 REQUIREMENTS - ELECTRICAL DEVICE

IGNITION PROTECTION

1.6 J If LPG is provided on a boat, unattended
potential sources of ignition of an electrical nature below
the main deck shall be ignition protected in accordance
with SAE J1171, "External Ignition Protection of Marine
Electrical Devices" or UL 1500, "Ignition Protection Test
for Marine Products" if located in compartments
containing LPG appliances, cylinders, fittings, valves or
regulators. (SeeABYC E-8, E-9).

EXCEPTIONS: 1.

Accommodation spaces.

2. Open compartments having

at least IS square inches of open area
per cubic foot of net compartment
volume (0.34 m 2 open area per m 3 )
exposed to the open atmosphere
outside the craft.

1.7

CYLINDERS

1.7.1 Cylinders used in LPG systems shall meet
applicable DOT or ASME regulations.

1 .8 CYLINDER VAL \<"ES AND SAFETY

DEUCES

1.8.1 A readily accessible manual or electrically
operated (solenoid) shut-off valve shall be installed in the
low or high pressure line at the fuel supply (see A-l. 12 for

© 1993 American Boat and Yacht Council, Inc.
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valve location). The valve(s) or its control must be
operable from the vicinity of the appliance(s) in the event
of a fire at any appliance(s). If the cylinder valve is
readily accessible from the vicinity of the appliance, the
shut-off valve on the supply line is not required

1.8.2 In addition to the valve required at the cylinder,
a multiple cylinder system shall be provided with a shut-
off valve, or automatic check valve, at the cylinder
manifold such that each cylinder can be isolated from
pressure feedback from other cylinders.

1 .8.3 Cylinder valves and safety relief devices shall be
installed in, or be directly connected to the vapor space or
cylinder.

1.11
LINES

LOCATION AND INSTALLATION - FUEL

1.9

PRESSURE REGULA TORS

1.9.1 Each LPG system shall be provided with a
pressure regulator specifically designed for use with LPG,

1.9.2 The LPG pressure regulator shall be adjusted to
deliver gas at any or each appliance, under varying
appliance loads, at a pressure not in excess of 50 mbar (19
inches water column, approximately 0.735 psig).

1.9.3 A low-side pressure relief device shall be
integral with each regulating system. It shall discharge at
between two times and tliree times the delivery pressure of
the regulator,

1.9.4 All relief valve outlets shall discharge into the
locker or to the open atmosphere. The point of discharge
shall be at least two feet distance from any opening to a
cabin or the hull interior or from any engine exhaust
terminus which is below the level of the vent discharge.

1-1 1.1 Fuel supply lines shall be protected from
physical damage and shall be accessible for inspection,

1.11.2 A flexible section shall be used to allow the free
swing of gimbaled stoves,

1.11.3 Fuel supply lines shall be supported by clips or
straps or other suitable means such as conduit or tray to
prevent vibration damage. The clips or straps or other
devices shall be corrosion resistant and shall be designed
to prevent cutting, abrading or damage to the lines and
shall be compatible with fuel supply line material,

1.11.4 Fuel supply lines shall be protected by close-
fitting grommets, sleeves or sealants of non-abrasive
material wherever they pass through decks, or watertight
bulkheads and the method used shall be watertight,

1.11.5 Fuel supply lines passing through bulkheads that
need not be watertight shall be installed so that the
bulkheads will not cut, abrade or damage the line.

1.11.6 Fuel supply lines shall be continuous lengths of
tubing, piping or hose from the regulating device, solenoid
valve or leak detector to the appliance or to the flexible
section at the appliance.

1.11.7 Each appliance shall be served by a separate low
pressure (50 mb) regulated supply line which shall
originate inside the cylinder locker or protective enclosure.

1.11.8 LPG fuel supply lines shall not be used for an
electrical ground.

1.10

FUEL SUPPLY LINES

1.10.1 The fuel supply line system and its components,
as installed, shall be designed to be compatible with LPG
and to withstand the stresses and exposure to the marine
environment. One type is annealed copper tubing,
standard type, Grade K or L, conforming to Specifications
for Seamless Copper Water Tube (ASTM B88-75a) with a
wall thickness of not less than 0.815 nun (0.032"),

1.10.2 The flexible LPG fuel line shall comply with UL
21 LP Gas Hose.

1,12 LOCATION AND INSTALLATION -
CYLINDER AND CONNECTED DEUCES

LPG cylinders, cylinder valves, safety devices and
regulating equipment shall be secured for sea conditions
and readily accessible, and shall be located;

1, 12, 1 on the exterior of the boat where escaping gases
will flow directly overboard, the cylinder valve, regulators,
and safety devices shall be in a ventilated location
protected from the weather and against mechanical
damage, or

1 , 10.3 LPG supply hose shall be equipped with
permanently attached end fittings, such as a swaged sleeve
or sleeve and threaded insert

1,10,4 Metal tubing shall be connected by means of
flare fittings. Metal to metal compression sleeve type
fittings shall not be used.

L 12.2 in a dedicated locker which shall be:

1.12.2.1 vapor tight to the hull interior,

1.12.2.2 located above the waterline,

1.12.2.3 constructed of or lined with corrosion resistant
materials,

© 1993 American Boat and Yacht Council, hie.

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L12.2.4 equipped with gasketed cover which:

L 12.2.4.1 opens directly to the atmosphere outside the
boat,

L 12.2.4.2 opens only from the top,

1.12.2.4.3 latches tightly,

1.12.2.4.4 is capable of being quickly and conveniently
opened without tools for operating the cylinder valves,
testing the system for leakage and viewing the pressure
gauge.

1 . 12. 2,5 vented at the bottom by a dedicated vent,

1.12.2.5.1 led outboard without pockets through the hull
sides to a point lower than the locker bottom but above the
waterline,

1. 12.2.5.2 located at least two feet distant from any hull
opening to the boat interior, and

1.12.2.5.3 located at least two feet distant from an
engine exhaust terminus which is below the level of a vent
outlet.

1.12.2.5.4 with a minimum diameter of any component
in the vent system not less than 12.5 mm (1/2 inch) inside
diameter.

1.12.3 When means of access to the locker or housing is
open, the cylinder valves shall be capable of being
conveniently and quickly operated and the system pressure
gauge dials shall be fully visible.

1.12.4 Storage provisions for unconnected reserve
cylinders, filled or empty, shall be the same as for the
cylinder in use.

1.12.5 Lockers shall not be used for storage of any other
equipment.

With the appliance valves oil', open the cylinder supply
valve. Close the cylinder supply valve. Observe the
pressure gauge reading. The pressure indicated should
remain constant for not less than three minutes, If any
leakage is indicated by a drop in pressure, check the
entire system with a leak detection fluid or detergent
solution to locate the leak. Test solutions shall be non-
corrosive and non-toxic. Repairs shall be made before
operating the system.

NOTES: L NEl^ER USE FLAME TO

CHECK FOR LEAKS!

2. NEWR USE SOLUTIONS

CONTAINING AMMONIA. AMMONIA,
MUCH IS PRESENT IN SOAPS AND
DETERGENT ATTACKS BRsiSS FITTINGS.
UNDETECTABLE AT FIRST, IN A MATTER
OF MONTHS THESE FITTINGS MAY
DEl^ELOP CRACKS AND LEAKS.

APPENDIX FOLLOWS

L13

TESTING

1.13.1 The fuel supply line and fittings shall be tested
with air pressure of not less than 34.5 kPa (5 psig). This
test shall be after installation, but prior to its connection to
the regulator and appliance(s).

1.13.2 The cylinder valve shall be checked for leakage
at its connection to the cylinder by application of a leak
detection fluid prior to connection to the system.

1.13.3 After the above tests, the complete system shall be
connected and shall be subjected to the following pressure
test:

© 1993 American Boat and Yacht Council, Inc.
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APPENDIX- LIQUEFIED PETROLEUM GAS SYSTEMS (LPG)

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This appendix provides information about and properties
of Liquefied Petroleum Gas (LPG). For similar
information about and properties of Compressed Natural
Gas (CNG), see ABYC A-22 "Marine - Compressed
Natural Gas Systems (CNG) " Appendix.

PROPERTIES OF GASES

NOTE: In the interest of safety, it is important that the
properties of Liquefied Petroleum Gas (I,PG) be
understood and that safe practices for its use be
followed It is also important that the difference in
properties between Liquefied Petroleum Gas (I,PG) and
Compressed Natural Gas (CNG) f as covered in ABYC
A~22 t Marine - Compressed Natural Gas Systents
(CNG) ", be compared to distinguish between these t>vo
types of fuels and their respective hazards.

A-l.Ap.l. LPG - Liquefied Petroleum Gas is two-
phased (liquid/vapor) fuel with a higher calorific valve
than Compressed Natural Gas (CNG) and is stored at a
lower cylinder pressure than CNG.

A-l.Ap.2. LPG is heavier than air and will fall or
settle if released.

A-l.Ap.3 LPG, in a natural state, is non-toxic and
invisible, but can displace the air necessary to sustain life,

A-l.Ap.4 Commercially available LPG, by law, has
an odorant added to facilitate leak detection. Since LPG is
a two-phased (liquid/vapor) fuel, the odor concentration
can vary depending on the volume of fuel remaining in the
cylinder.

A-l.Ap.5 The properties of LPG must be understood.
They are gases at normal room temperature and
atmospheric pressure. Under moderate pressure they
liquefy, vaporizing upon release of the pressure. It is this
property which permits the convenience of transporting
and storing these hydrocarbons in concentrated form while
normally using them in a vapor form.

A-LAp.6 Released from its liquid state, unignited gas
tends to sink to the bottom of an enclosed compartment.
Gas that is diffused throughout the compartment is not
readily dispelled by overhead ventilation. If mixed with
air in certain proportions and confined it will explode if
ignited In its gaseous state LPG presents a fire and
explosion hazard,

A-l.Ap,7 Cylinders shipped by land or air freight
must be packed and marked in accordance with DOT
regulations.

TABLE 1 - PROPERTIES OF LPG

PROPERTIES

COMPONENTS OF
LPG

Propane

Butane

Formula

C3H8

C4H10

Boiling Point, F

-44

32

Specific Gravity of Gas (Air = 1.00)

1.53

2.00

Specific Gravity of Liquid

(Water =1.00)

0.51

0.58

Lbs. per Gallon of Liquid at 60°F

4.24

4.81

BTU per Gallon of Gas at 60°F

91690

102032

BTU per Lb. of Gas

21591

21221

BTU per Cu. Ft. of Gas at 60°F

2516

3280

Cu. Ft. of Vapor at 60°F/GaL of
Liquid at 60°F

36.39

31.26

Cu, Ft. of Vapor at 60°F/Lb. of
Liquid at 60°F

8.547

6.506

Combustion Data:

Cu. Ft, Air Required to Burn

1 Cu. Ft. Gas

23.86

31.02

Ignition Temperature in Air, F

920-1020

900-1000

Maximum Flame Temperature in
Air,F

3595

3615

Limits of Inflammability,
Percentage of Gas in Air Mixture:
At Lower Limit - %
At Upper Limit - %

2.4
9.6

1.9
8.6

Flame Propagation Rate Feet per
second

2800

3000

Normal Cylinder Storage Pressure

@ 100° F

@ 70° F 1

172 PSI
109 PSI 1

37.5 PSI
17.0 PSI

ABYC Technical Board Rules provide that:

All technical reports, inclining reconwierided technical
practices and engineering standards, are advisory only;
their \use u (entirely : voluntary; [

Prospective users of the Arne^

recommended technical: i^

standards are "responsible ^fbmprotecting theviselves

against liability for infringement of patents.

The:^

responsibility^
technical ^practic
promulgated r by:it:^::

*****

© 1993 American Boat and Yacht Council, Inc.